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//===-- Host.cpp ----------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// C includes
#include <errno.h>
#include <limits.h>
#include <stdlib.h>
#include <sys/types.h>
#ifndef _WIN32
#include <dlfcn.h>
#include <grp.h>
#include <netdb.h>
#include <pwd.h>
#include <sys/stat.h>
#include <unistd.h>
#endif
#if defined(__APPLE__)
#include <mach-o/dyld.h>
#include <mach/mach_init.h>
#include <mach/mach_port.h>
#endif
#if defined(__linux__) || defined(__FreeBSD__) || \
defined(__FreeBSD_kernel__) || defined(__APPLE__) || \
defined(__NetBSD__) || defined(__OpenBSD__) || defined(__EMSCRIPTEN__)
#if !defined(__ANDROID__)
#include <spawn.h>
#endif
#include <sys/syscall.h>
#include <sys/wait.h>
#endif
#if defined(__FreeBSD__)
#include <pthread_np.h>
#endif
#if defined(__NetBSD__)
#include <lwp.h>
#endif
#include <csignal>
#include "lldb/Host/FileAction.h"
#include "lldb/Host/FileSystem.h"
#include "lldb/Host/Host.h"
#include "lldb/Host/HostInfo.h"
#include "lldb/Host/HostProcess.h"
#include "lldb/Host/MonitoringProcessLauncher.h"
#include "lldb/Host/ProcessLaunchInfo.h"
#include "lldb/Host/ProcessLauncher.h"
#include "lldb/Host/ThreadLauncher.h"
#include "lldb/Host/posix/ConnectionFileDescriptorPosix.h"
#include "lldb/Utility/DataBufferLLVM.h"
#include "lldb/Utility/FileSpec.h"
#include "lldb/Utility/Log.h"
#include "lldb/Utility/Predicate.h"
#include "lldb/Utility/ReproducerProvider.h"
#include "lldb/Utility/Status.h"
#include "lldb/lldb-private-forward.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/Support/Errno.h"
#include "llvm/Support/FileSystem.h"
#if defined(_WIN32)
#include "lldb/Host/windows/ConnectionGenericFileWindows.h"
#include "lldb/Host/windows/ProcessLauncherWindows.h"
#else
#include "lldb/Host/posix/ProcessLauncherPosixFork.h"
#endif
#if defined(__APPLE__)
#ifndef _POSIX_SPAWN_DISABLE_ASLR
#define _POSIX_SPAWN_DISABLE_ASLR 0x0100
#endif
extern "C" {
int __pthread_chdir(const char *path);
int __pthread_fchdir(int fildes);
}
#endif
using namespace lldb;
using namespace lldb_private;
#if !defined(__APPLE__) && !defined(_WIN32)
struct MonitorInfo {
lldb::pid_t pid; // The process ID to monitor
Host::MonitorChildProcessCallback
callback; // The callback function to call when "pid" exits or signals
bool monitor_signals; // If true, call the callback when "pid" gets signaled.
};
static thread_result_t MonitorChildProcessThreadFunction(void *arg);
llvm::Expected<HostThread> Host::StartMonitoringChildProcess(
const Host::MonitorChildProcessCallback &callback, lldb::pid_t pid,
bool monitor_signals) {
MonitorInfo *info_ptr = new MonitorInfo();
info_ptr->pid = pid;
info_ptr->callback = callback;
info_ptr->monitor_signals = monitor_signals;
char thread_name[256];
::snprintf(thread_name, sizeof(thread_name),
"<lldb.host.wait4(pid=%" PRIu64 ")>", pid);
return ThreadLauncher::LaunchThread(
thread_name, MonitorChildProcessThreadFunction, info_ptr, 0);
}
#ifndef __linux__
// Scoped class that will disable thread canceling when it is constructed, and
// exception safely restore the previous value it when it goes out of scope.
class ScopedPThreadCancelDisabler {
public:
ScopedPThreadCancelDisabler() {
// Disable the ability for this thread to be cancelled
int err = ::pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &m_old_state);
if (err != 0)
m_old_state = -1;
}
~ScopedPThreadCancelDisabler() {
// Restore the ability for this thread to be cancelled to what it
// previously was.
if (m_old_state != -1)
::pthread_setcancelstate(m_old_state, 0);
}
private:
int m_old_state; // Save the old cancelability state.
};
#endif // __linux__
#ifdef __linux__
#if defined(__GNUC__) && (__GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 8))
static __thread volatile sig_atomic_t g_usr1_called;
#else
static thread_local volatile sig_atomic_t g_usr1_called;
#endif
static void SigUsr1Handler(int) { g_usr1_called = 1; }
#endif // __linux__
static bool CheckForMonitorCancellation() {
#ifdef __linux__
if (g_usr1_called) {
g_usr1_called = 0;
return true;
}
#else
::pthread_testcancel();
#endif
return false;
}
static thread_result_t MonitorChildProcessThreadFunction(void *arg) {
Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_PROCESS));
const char *function = __FUNCTION__;
LLDB_LOGF(log, "%s (arg = %p) thread starting...", function, arg);
MonitorInfo *info = (MonitorInfo *)arg;
const Host::MonitorChildProcessCallback callback = info->callback;
const bool monitor_signals = info->monitor_signals;
assert(info->pid <= UINT32_MAX);
const ::pid_t pid = monitor_signals ? -1 * getpgid(info->pid) : info->pid;
delete info;
int status = -1;
#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__OpenBSD__)
#define __WALL 0
#endif
const int options = __WALL;
#ifdef __linux__
// This signal is only used to interrupt the thread from waitpid
struct sigaction sigUsr1Action;
memset(&sigUsr1Action, 0, sizeof(sigUsr1Action));
sigUsr1Action.sa_handler = SigUsr1Handler;
::sigaction(SIGUSR1, &sigUsr1Action, nullptr);
#endif // __linux__
while (1) {
log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_PROCESS);
LLDB_LOGF(log, "%s ::waitpid (pid = %" PRIi32 ", &status, options = %i)...",
function, pid, options);
if (CheckForMonitorCancellation())
break;
// Get signals from all children with same process group of pid
const ::pid_t wait_pid = ::waitpid(pid, &status, options);
if (CheckForMonitorCancellation())
break;
if (wait_pid == -1) {
if (errno == EINTR)
continue;
else {
LLDB_LOG(log,
"arg = {0}, thread exiting because waitpid failed ({1})...",
arg, llvm::sys::StrError());
break;
}
} else if (wait_pid > 0) {
bool exited = false;
int signal = 0;
int exit_status = 0;
const char *status_cstr = nullptr;
if (WIFSTOPPED(status)) {
signal = WSTOPSIG(status);
status_cstr = "STOPPED";
} else if (WIFEXITED(status)) {
exit_status = WEXITSTATUS(status);
status_cstr = "EXITED";
exited = true;
} else if (WIFSIGNALED(status)) {
signal = WTERMSIG(status);
status_cstr = "SIGNALED";
if (wait_pid == abs(pid)) {
exited = true;
exit_status = -1;
}
} else {
status_cstr = "(\?\?\?)";
}
// Scope for pthread_cancel_disabler
{
#ifndef __linux__
ScopedPThreadCancelDisabler pthread_cancel_disabler;
#endif
log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_PROCESS);
LLDB_LOGF(log,
"%s ::waitpid (pid = %" PRIi32
", &status, options = %i) => pid = %" PRIi32
", status = 0x%8.8x (%s), signal = %i, exit_state = %i",
function, pid, options, wait_pid, status, status_cstr, signal,
exit_status);
if (exited || (signal != 0 && monitor_signals)) {
bool callback_return = false;
if (callback)
callback_return = callback(wait_pid, exited, signal, exit_status);
// If our process exited, then this thread should exit
if (exited && wait_pid == abs(pid)) {
LLDB_LOGF(log,
"%s (arg = %p) thread exiting because pid received "
"exit signal...",
__FUNCTION__, arg);
break;
}
// If the callback returns true, it means this process should exit
if (callback_return) {
LLDB_LOGF(log,
"%s (arg = %p) thread exiting because callback "
"returned true...",
__FUNCTION__, arg);
break;
}
}
}
}
}
log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_PROCESS);
LLDB_LOGF(log, "%s (arg = %p) thread exiting...", __FUNCTION__, arg);
return nullptr;
}
#endif // #if !defined (__APPLE__) && !defined (_WIN32)
#if !defined(__APPLE__)
void Host::SystemLog(SystemLogType type, const char *format, va_list args) {
vfprintf(stderr, format, args);
}
#endif
void Host::SystemLog(SystemLogType type, const char *format, ...) {
{
va_list args;
va_start(args, format);
SystemLog(type, format, args);
va_end(args);
}
Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST));
if (log && log->GetVerbose()) {
// Log to log channel. This allows testcases to grep for log output.
va_list args;
va_start(args, format);
log->VAPrintf(format, args);
va_end(args);
}
}
lldb::pid_t Host::GetCurrentProcessID() { return ::getpid(); }
#ifndef _WIN32
lldb::thread_t Host::GetCurrentThread() {
return lldb::thread_t(pthread_self());
}
const char *Host::GetSignalAsCString(int signo) {
switch (signo) {
case SIGHUP:
return "SIGHUP"; // 1 hangup
case SIGINT:
return "SIGINT"; // 2 interrupt
case SIGQUIT:
return "SIGQUIT"; // 3 quit
case SIGILL:
return "SIGILL"; // 4 illegal instruction (not reset when caught)
case SIGTRAP:
return "SIGTRAP"; // 5 trace trap (not reset when caught)
case SIGABRT:
return "SIGABRT"; // 6 abort()
#if defined(SIGPOLL)
#if !defined(SIGIO) || (SIGPOLL != SIGIO)
// Under some GNU/Linux, SIGPOLL and SIGIO are the same. Causing the build to
// fail with 'multiple define cases with same value'
case SIGPOLL:
return "SIGPOLL"; // 7 pollable event ([XSR] generated, not supported)
#endif
#endif
#if defined(SIGEMT)
case SIGEMT:
return "SIGEMT"; // 7 EMT instruction
#endif
case SIGFPE:
return "SIGFPE"; // 8 floating point exception
case SIGKILL:
return "SIGKILL"; // 9 kill (cannot be caught or ignored)
case SIGBUS:
return "SIGBUS"; // 10 bus error
case SIGSEGV:
return "SIGSEGV"; // 11 segmentation violation
case SIGSYS:
return "SIGSYS"; // 12 bad argument to system call
case SIGPIPE:
return "SIGPIPE"; // 13 write on a pipe with no one to read it
case SIGALRM:
return "SIGALRM"; // 14 alarm clock
case SIGTERM:
return "SIGTERM"; // 15 software termination signal from kill
case SIGURG:
return "SIGURG"; // 16 urgent condition on IO channel
case SIGSTOP:
return "SIGSTOP"; // 17 sendable stop signal not from tty
case SIGTSTP:
return "SIGTSTP"; // 18 stop signal from tty
case SIGCONT:
return "SIGCONT"; // 19 continue a stopped process
case SIGCHLD:
return "SIGCHLD"; // 20 to parent on child stop or exit
case SIGTTIN:
return "SIGTTIN"; // 21 to readers pgrp upon background tty read
case SIGTTOU:
return "SIGTTOU"; // 22 like TTIN for output if (tp->t_local&LTOSTOP)
#if defined(SIGIO)
case SIGIO:
return "SIGIO"; // 23 input/output possible signal
#endif
case SIGXCPU:
return "SIGXCPU"; // 24 exceeded CPU time limit
case SIGXFSZ:
return "SIGXFSZ"; // 25 exceeded file size limit
case SIGVTALRM:
return "SIGVTALRM"; // 26 virtual time alarm
case SIGPROF:
return "SIGPROF"; // 27 profiling time alarm
#if defined(SIGWINCH)
case SIGWINCH:
return "SIGWINCH"; // 28 window size changes
#endif
#if defined(SIGINFO)
case SIGINFO:
return "SIGINFO"; // 29 information request
#endif
case SIGUSR1:
return "SIGUSR1"; // 30 user defined signal 1
case SIGUSR2:
return "SIGUSR2"; // 31 user defined signal 2
default:
break;
}
return nullptr;
}
#endif
#if !defined(__APPLE__) // see Host.mm
bool Host::GetBundleDirectory(const FileSpec &file, FileSpec &bundle) {
bundle.Clear();
return false;
}
bool Host::ResolveExecutableInBundle(FileSpec &file) { return false; }
#endif
#ifndef _WIN32
FileSpec Host::GetModuleFileSpecForHostAddress(const void *host_addr) {
FileSpec module_filespec;
#if !defined(__ANDROID__)
Dl_info info;
if (::dladdr(host_addr, &info)) {
if (info.dli_fname) {
module_filespec.SetFile(info.dli_fname, FileSpec::Style::native);
FileSystem::Instance().Resolve(module_filespec);
}
}
#endif
return module_filespec;
}
#endif
#if !defined(__linux__)
bool Host::FindProcessThreads(const lldb::pid_t pid, TidMap &tids_to_attach) {
return false;
}
#endif
struct ShellInfo {
ShellInfo()
: process_reaped(false), pid(LLDB_INVALID_PROCESS_ID), signo(-1),
status(-1) {}
lldb_private::Predicate<bool> process_reaped;
lldb::pid_t pid;
int signo;
int status;
};
static bool
MonitorShellCommand(std::shared_ptr<ShellInfo> shell_info, lldb::pid_t pid,
bool exited, // True if the process did exit
int signo, // Zero for no signal
int status) // Exit value of process if signal is zero
{
shell_info->pid = pid;
shell_info->signo = signo;
shell_info->status = status;
// Let the thread running Host::RunShellCommand() know that the process
// exited and that ShellInfo has been filled in by broadcasting to it
shell_info->process_reaped.SetValue(true, eBroadcastAlways);
return true;
}
Status Host::RunShellCommand(llvm::StringRef command,
const FileSpec &working_dir, int *status_ptr,
int *signo_ptr, std::string *command_output_ptr,
const Timeout<std::micro> &timeout,
bool run_in_shell, bool hide_stderr) {
return RunShellCommand(llvm::StringRef(), Args(command), working_dir,
status_ptr, signo_ptr, command_output_ptr, timeout,
run_in_shell, hide_stderr);
}
Status Host::RunShellCommand(llvm::StringRef shell_path,
llvm::StringRef command,
const FileSpec &working_dir, int *status_ptr,
int *signo_ptr, std::string *command_output_ptr,
const Timeout<std::micro> &timeout,
bool run_in_shell, bool hide_stderr) {
return RunShellCommand(shell_path, Args(command), working_dir, status_ptr,
signo_ptr, command_output_ptr, timeout, run_in_shell,
hide_stderr);
}
Status Host::RunShellCommand(const Args &args, const FileSpec &working_dir,
int *status_ptr, int *signo_ptr,
std::string *command_output_ptr,
const Timeout<std::micro> &timeout,
bool run_in_shell, bool hide_stderr) {
return RunShellCommand(llvm::StringRef(), args, working_dir, status_ptr,
signo_ptr, command_output_ptr, timeout, run_in_shell,
hide_stderr);
}
Status Host::RunShellCommand(llvm::StringRef shell_path, const Args &args,
const FileSpec &working_dir, int *status_ptr,
int *signo_ptr, std::string *command_output_ptr,
const Timeout<std::micro> &timeout,
bool run_in_shell, bool hide_stderr) {
Status error;
ProcessLaunchInfo launch_info;
launch_info.SetArchitecture(HostInfo::GetArchitecture());
if (run_in_shell) {
// Run the command in a shell
FileSpec shell = HostInfo::GetDefaultShell();
if (!shell_path.empty())
shell.SetPath(shell_path);
launch_info.SetShell(shell);
launch_info.GetArguments().AppendArguments(args);
const bool will_debug = false;
const bool first_arg_is_full_shell_command = false;
launch_info.ConvertArgumentsForLaunchingInShell(
error, will_debug, first_arg_is_full_shell_command, 0);
} else {
// No shell, just run it
const bool first_arg_is_executable = true;
launch_info.SetArguments(args, first_arg_is_executable);
}
launch_info.GetEnvironment() = Host::GetEnvironment();
if (working_dir)
launch_info.SetWorkingDirectory(working_dir);
llvm::SmallString<64> output_file_path;
if (command_output_ptr) {
// Create a temporary file to get the stdout/stderr and redirect the output
// of the command into this file. We will later read this file if all goes
// well and fill the data into "command_output_ptr"
if (FileSpec tmpdir_file_spec = HostInfo::GetProcessTempDir()) {
tmpdir_file_spec.AppendPathComponent("lldb-shell-output.%%%%%%");
llvm::sys::fs::createUniqueFile(tmpdir_file_spec.GetPath(),
output_file_path);
} else {
llvm::sys::fs::createTemporaryFile("lldb-shell-output.%%%%%%", "",
output_file_path);
}
}
FileSpec output_file_spec(output_file_path.str());
// Set up file descriptors.
launch_info.AppendSuppressFileAction(STDIN_FILENO, true, false);
if (output_file_spec)
launch_info.AppendOpenFileAction(STDOUT_FILENO, output_file_spec, false,
true);
else
launch_info.AppendSuppressFileAction(STDOUT_FILENO, false, true);
if (output_file_spec && !hide_stderr)
launch_info.AppendDuplicateFileAction(STDOUT_FILENO, STDERR_FILENO);
else
launch_info.AppendSuppressFileAction(STDERR_FILENO, false, true);
std::shared_ptr<ShellInfo> shell_info_sp(new ShellInfo());
const bool monitor_signals = false;
launch_info.SetMonitorProcessCallback(
std::bind(MonitorShellCommand, shell_info_sp, std::placeholders::_1,
std::placeholders::_2, std::placeholders::_3,
std::placeholders::_4),
monitor_signals);
error = LaunchProcess(launch_info);
const lldb::pid_t pid = launch_info.GetProcessID();
if (error.Success() && pid == LLDB_INVALID_PROCESS_ID)
error.SetErrorString("failed to get process ID");
if (error.Success()) {
if (!shell_info_sp->process_reaped.WaitForValueEqualTo(true, timeout)) {
error.SetErrorString("timed out waiting for shell command to complete");
// Kill the process since it didn't complete within the timeout specified
Kill(pid, SIGKILL);
// Wait for the monitor callback to get the message
shell_info_sp->process_reaped.WaitForValueEqualTo(
true, std::chrono::seconds(1));
} else {
if (status_ptr)
*status_ptr = shell_info_sp->status;
if (signo_ptr)
*signo_ptr = shell_info_sp->signo;
if (command_output_ptr) {
command_output_ptr->clear();
uint64_t file_size =
FileSystem::Instance().GetByteSize(output_file_spec);
if (file_size > 0) {
if (file_size > command_output_ptr->max_size()) {
error.SetErrorStringWithFormat(
"shell command output is too large to fit into a std::string");
} else {
auto Buffer =
FileSystem::Instance().CreateDataBuffer(output_file_spec);
if (error.Success())
command_output_ptr->assign(Buffer->GetChars(),
Buffer->GetByteSize());
}
}
}
}
}
llvm::sys::fs::remove(output_file_spec.GetPath());
return error;
}
// The functions below implement process launching for non-Apple-based
// platforms
#if !defined(__APPLE__)
Status Host::LaunchProcess(ProcessLaunchInfo &launch_info) {
std::unique_ptr<ProcessLauncher> delegate_launcher;
#if defined(_WIN32)
delegate_launcher.reset(new ProcessLauncherWindows());
#else
delegate_launcher.reset(new ProcessLauncherPosixFork());
#endif
MonitoringProcessLauncher launcher(std::move(delegate_launcher));
Status error;
HostProcess process = launcher.LaunchProcess(launch_info, error);
// TODO(zturner): It would be better if the entire HostProcess were returned
// instead of writing it into this structure.
launch_info.SetProcessID(process.GetProcessId());
return error;
}
#endif // !defined(__APPLE__)
#ifndef _WIN32
void Host::Kill(lldb::pid_t pid, int signo) { ::kill(pid, signo); }
#endif
#if !defined(__APPLE__)
bool Host::OpenFileInExternalEditor(const FileSpec &file_spec,
uint32_t line_no) {
return false;
}
#endif
std::unique_ptr<Connection> Host::CreateDefaultConnection(llvm::StringRef url) {
#if defined(_WIN32)
if (url.startswith("file://"))
return std::unique_ptr<Connection>(new ConnectionGenericFile());
#endif
return std::unique_ptr<Connection>(new ConnectionFileDescriptor());
}
#if defined(LLVM_ON_UNIX)
WaitStatus WaitStatus::Decode(int wstatus) {
if (WIFEXITED(wstatus))
return {Exit, uint8_t(WEXITSTATUS(wstatus))};
else if (WIFSIGNALED(wstatus))
return {Signal, uint8_t(WTERMSIG(wstatus))};
else if (WIFSTOPPED(wstatus))
return {Stop, uint8_t(WSTOPSIG(wstatus))};
llvm_unreachable("Unknown wait status");
}
#endif
void llvm::format_provider<WaitStatus>::format(const WaitStatus &WS,
raw_ostream &OS,
StringRef Options) {
if (Options == "g") {
char type;
switch (WS.type) {
case WaitStatus::Exit:
type = 'W';
break;
case WaitStatus::Signal:
type = 'X';
break;
case WaitStatus::Stop:
type = 'S';
break;
}
OS << formatv("{0}{1:x-2}", type, WS.status);
return;
}
assert(Options.empty());
const char *desc;
switch(WS.type) {
case WaitStatus::Exit:
desc = "Exited with status";
break;
case WaitStatus::Signal:
desc = "Killed by signal";
break;
case WaitStatus::Stop:
desc = "Stopped by signal";
break;
}
OS << desc << " " << int(WS.status);
}
uint32_t Host::FindProcesses(const ProcessInstanceInfoMatch &match_info,
ProcessInstanceInfoList &process_infos) {
if (llvm::Optional<ProcessInstanceInfoList> infos =
repro::GetReplayProcessInstanceInfoList()) {
process_infos = *infos;
return process_infos.size();
}
uint32_t result = FindProcessesImpl(match_info, process_infos);
if (repro::Generator *g = repro::Reproducer::Instance().GetGenerator()) {
g->GetOrCreate<repro::ProcessInfoProvider>()
.GetNewProcessInfoRecorder()
->Record(process_infos);
}
return result;
}